Hurricane Olaf was a Category 2 Pacific hurricane that struck the Baja California Peninsula in September 2021. The fifteenth named storm and sixth hurricane of the 2021 Pacific hurricane season, the cyclone formed from an area of low pressure that developed off the southwestern coast of Mexico on September 5, 2021. The disturbance developed within a favorable environment, acquiring more convection and a closed surface circulation. The disturbance developed into Tropical Depression Fifteen-E by 18:00 UTC on September 7. The depression strengthened into a tropical storm and was named Olaf at 12:00 UTC the next day. Olaf quickly strengthened as it moved to the north-northwest, and was upgraded to a hurricane 24 hours after being named. Hurricane Olaf continued to intensify and reached peak intensity while its center was just offshore the southwestern coast of Baja California Sur, with maximum sustained winds of 105 mph (169 km/h) and a minimum barometric pressure of 975 mbar (28.8 inHg). Just after reaching peak intensity, the hurricane made landfall near San José del Cabo. Interaction with the mountainous terrain of the Baja California Peninsula caused Olaf to quickly weaken. It was downgraded to a tropical storm at 12:00 UTC on September 10. The system became devoid of convection later that day and degenerated to a remnant low by 06:00 UTC on September 11.

The 2021 Pacific hurricane season was a moderately active Pacific hurricane season, with above-average activity in terms of number of named storms, but below-average activity in terms of major hurricanes, as 19 named storms, 8 hurricanes, and 2 major hurricanes formed in all. It also had a near-normal accumulated cyclone energy (ACE). The season officially began on May 15, 2021 in the Eastern Pacific Ocean, and on June 1, 2021, in the Central Pacific in the Northern Hemisphere. The season ended in both regions on November 30, 2021. These dates historically describe the period each year when most tropical cyclogenesis occurs in these regions of the Pacific and are adopted by convention. However, the formation of tropical cyclones is possible at any time of the year, as illustrated by the formation of Tropical Storm Andres on May 9, which was the earliest forming tropical storm on record in the Eastern Pacific. Conversely, 2021 was the second consecutive season in which no tropical cyclones formed in the Central Pacific.